This example demonstrates several D3.js data transformation techniques on the classic Iris flower dataset. The visualization displays the raw data from a CSV file in a styled preformatted block, while the console logs the results of operations including `d3.min`, `d3.max`, `d3.extent`, `d3.group`, `d3.rollup`, and `d3.bin`. Using D3 v7 APIs like `flatGroup` and `flatRollup`, it shows how to aggregate observations by species and compute averages, culminating in a histogram of sepal lengths generated with `d3.bin`. The code loads data asynchronously via `d3.csvParse` after a fetch request.